Genetics of Nitrogen Fixation in the Bacterium Klebsiella Pneumoniae

Abstract

The reader may be somewhat surprised to find a contribution concerning a prokaryotic organism in a symposium devoted to the organisation and expression of plant cell genomes. It is well- established however that nitrogen-fixing micro-organisms contribute directly or indirectly to the nitrogen economy of higher plants and it is well known that some nitrogen-fixing bacteria are specifically able to form beneficial symbiotic associations with certain plants. In view of the importance of biological nitrogen fixation in the nitrogen cycle and the increasing demands on world agriculture, it is not surprising that there is considerable interest in the genetic manipulation of nitrogen fixation, particularly in regard to cereal crops. The aim of this paper is to provide the plant cell biologist with an overview of genetic research in a well-studied nitrogen fixing prokaryote; future potential for genetic engineering of nitrogen fixation (nif) can then perhaps be seen in its proper perspective.